More rainbows for Kootenay Lake
The Lardeau River Side Channel Enhancement Project will provide habitat for juvenile Gerrard rainbow trout
In the fall of 2013, Columbia Power Corporation will undertake the Lardeau River Side Channel Enhancement Project, to compensate for potential damage to fish populations resulting from the Brilliant Dam upgrades completed between 1999 and 2003.
The upgrades to the dam—which is situated on the Kootenay River near Castlegar, B.C.—involved installing new, more efficient turbines, but the increased flow through the turbines has meant a higher risk of fish mortality. With agency support and First Nations input, Columbia Power is pleased to have identified a project that will benefit the Gerrard rainbow trout and other fish in the region.
“We ourselves provided the information about the impact of the dam upgrades,” said Llewellyn Matthews of Columbia Power, “and we made the commitment to undertake compensation as required by Fisheries and Oceans Canada.”
Compensating for the losses
The Lardeau River system—which lies just northwest of Kootenay Lake—is the spawning and rearing ground for Gerrard rainbow trout, which commonly grow to five times the weight of other rainbow trout and are the world’s largest.
“They do well spawning,” said Matthews, “but there is limited existing habitat where they can overwinter and grow during (those) first few years before moving out to Kootenay Lake. The habitat that we’re creating is targeting that particular life phase.”
The compensation target is to provide habitat for 50 spawning pairs of rainbow trout, or 500 trout age one or older. Matthews said that the fish from this project will go into Kootenay Lake instead of the immediate head-pond of the Brilliant Dam farther south, as there was no site available in the immediate area of the Brilliant Dam that would support a project with this targeted amount.
“We looked at spawning-site enhancements and juvenile habitat enhancement, and the one that was determined to be of most value was oriented to providing habitat for juvenile rainbow trout,” Matthews said.
Choosing the site
Investigation of the area determined that one side channel of the Lardeau River (side channel 7.57R, measuring just over half a kilometre in length) is the most effective site to provide the needed habitat—but it needs a little work. At present, 7.57R is restricted at its inlet by accumulated rock and debris, and carries water only when the river's water level is high. Excavation and the clearing away of the debris will allow water to flow through the channel all year, and the installation of 12 habitat structures will enhance the habitat value of the side channel by providing cover and deeper pools for the juveniles. In-stream work will likely take seven to 10 days.
The enhanced side channel will provide benefits to other breeds of fish as well, with improved forage grounds, spawning grounds and safe retreats for when predators threaten. Environmental safeguards are integrated into the enhancement project plans.
“There will be an environmental management plan for the construction of the enhancement, to make sure that the construction doesn’t cause any environmental damage,” Matthews said.
Columbia Power thanks the agencies, stakeholders and public for their support and interest during the community open house held at the Meadow Creek Community Centre this past winter, and is looking forward to undertaking this project in fall 2013. For more information, please visit the Columbia Power website.